May'^iSr™" }        Glecmings  fi'om  Foreign  Journals.  237 
GLEANINGS  FROM  FOREIGN  JOURNALS. 
By  J.  Robp:rt  Moechel. 
Eucalyptol,  from  Eucalyptus  globulus,  according  to  C.  Jahns,  has 
the  formula,  QoHjgO,  boils  between  176-177°C.,  has  the  spec.  grav. 
•923  at  16°C.,  is  without  optic  action,  and  is  identical  with  cajuputol, 
as  it  shows  the  same  chemical  and  physical  properties.  He  corrobo- 
rates the  observation  of  Faust  and  Homayer  (1874),  that  the  eucalyp- 
tol  of  Cloez  was  a  mixture,  and  shows  that  Eucalyptolum  purissimum 
of  commerce  is  merely  rectified  oil  of  eucalyptus. — Arch.  d.  Pharm., 
January,  1885. 
Determination  of  the  Value  of  Pepsin. — O.  Schlickum  recommends 
for  this  purpose  the  conversion  of  albumen  into  peptone.  An  egg  is 
placed  in  boiling  water  for  five  minutes,  and  rapidly  cooled  by  cold 
water;  the  albumen  will  be  hard,  the  yolk  semi-liquid.  Cut  the  albu- 
men into  very  *fine  pieces,  and  rub  through  a  fine  sieve ;  of  this  albu- 
men put  10  Gm.  into  a  solution  of  O'l  pepsin  in  150  water,  add  2*5 
HCl  and  keep  the  mixture  at  a  temperature  of  40°C.  by  means  of  a 
water  bath.  On  being  dissolved,  the  albumen  is  trasformed  first  into 
hemialbumose,  and  afterward  into  peptone.  Digest  for  12  hours,  then 
filter,  and  to  10  cc.  of  the  filtrate  add,  drop  by  drop,  1  cc.  IINO3, 
which  should  not  cause  more  than  a  slight  opalescence. — Ph.  Ztg.,  No» 
16,  1885. 
Quantitative  Determination  of  Aloes. — According  to  H.  Hager,  aloes 
is  soluble  in  a  cold  solution  of  carbonate  of  sodium,  easily  soluble  in 
a  2  per  cent,  solution  of  ammonia,  entirely  so  in  80  per  cent,  alcohol, 
incompletely  in  90  per  cent,  and  absolute  alcohol,  insoluble  in  a  mix- 
ture of  1  vol.  of  absolute  alcohol,  2  vol.  of  chloroform,  and  3  vol.  of 
benzol.  To  determine  aloes  in  a  liquid,  evaporate,  dry  and  powder; 
exhaust  at  a  temperature  of  18°  to  25°C.  with  the  mixture  of  alcohol, 
chloroform  and  benzol,  to  separate  all  the  resinous  substances  soluble  in 
that  mixture,  and  dry  the  residue ;  digest  this  with  80  per  cent,  alco- 
hol at  a  temperature  near  50°C.,  frequently  shaking ;  place  the  result- 
ing solution  in  a  weighed  capsule,  evaporate  and  dry.  For  each  gram 
of  the  residue  use  12  to  15  cc.  of  a  2  per  cent,  solution  of  ammonia, 
to  dissolve  the  aloes ;  treat  the  resulting  solution  with  a  very  slight 
excess  of  a  solution  of  acetate  of  lead,  and  restore  a  slight  ammoni- 
acal  smell  by  adding  a  few  drops  of  ammonia  water.  Following  these 
directions,  the  aloes  is  entirely  precipitated  as  a  lead  compound.  Col- 
